From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Tibor Kircsi" Subject: Re: Current break round up Date: Wed, 1 Oct 2008 16:40:42 +0200 Message-ID: References: <1222802784.8421.10.camel@kirilla-desktop> <48E37E93.3080101@verizon.net> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to :subject:cc:in-reply-to:mime-version:content-type :content-transfer-encoding:content-disposition:references; bh=fxcWiu+m90mKPcVl2VtKaPPHK2tY1UrJRs8VxKhS2os=; b=d9+u7p5F7q8nJPH2xbCYjnphEAkSipoYBd9rq4e0k2a5g56Xgfo8oaRaAJ0Wi+EmLa UAAdC7R/5Y9LZdGA8um6LIlWe/oFgzIrw6zNGydoFONG4REJ2t5IHlzMaVpa95Iej8y+ S15rgLEXS8UoVrOS6K0G2+OBUBQIsi70tYvbE= In-Reply-To: <48E37E93.3080101@verizon.net> Content-Disposition: inline Sender: linux-assembly-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Frank Kotler Cc: linux-assembly@vger.kernel.org Hi, You're right! I tested it and I could write and read above the current break after I call brk. I'll will test the page border too. Thanks. regards, Tibor On Wed, Oct 1, 2008 at 3:43 PM, Frank Kotler wrote: > > Kircsi Tibor wrote: >> >> Hi, >> >> Sorry for my english. I started learn assembly again after 15 years. >> Now, I'm learning about memory management and sys_brk system call. I've >> created a really simple program, which try to extend the heap size. I've >> read, when sys_brk is called with the new break address(last usable >> address of the heap or data segment), it will be rounded up to the next >> nearest page, but it didn't. Am I misundestand somthing? > > I've noticed this. Seems to be related to kernel version (2.4.33.3 here). May be a "bug"? I think you can access memory up to the top of the page (what you/we would "expect" brk to return). I don't know what to make of it. > > Best, > Frank >